Black sulfur dye.



U ITED STATES PATENT GrrroE.

ARTHUR GEORGE GREEN, OF- HEATON MOOR, AND ALEXANDER MEYENBERG, OFMANCHESTER, ENGLAND.

BLACK SULFUR DYE.

SPECIFICATION formingpart of Letters Patent No. 641,588, dated January16, 1900.

Application filed September 29,1899. Serial No. 7323074- (Specimens) Toall whom it may concern.-

Be it known that we, ARTHUR GEORGE GREEN, F. I. C., F. C. S., a subjectof the Queen of Great Britain and Ireland, residing at 13 Kings Drive,Heaton Moor, near Stockport, and ALEXANDER ll/IEYENBERG, Ph. D., asubject of the Emperor of Germany, residing at 13 Nelson street,Ardwick, Manchester, England, have invented certain new and usefulImprovements in New Black Coloring-Matter; and we do hereby declare thefollowing to be a full, clear, and exact description of the invention,-such as will enable oth- 'ers skilled in the art to which it appertainsto make and use the same.

This invention (for which Letters Patent have been applied for inEngland, dated March 7, 1899 5 in Germany, dated November 27, 1898, andMay 24, 1899, and in France, dated May 3, 1899,) refers to theproduction of a new black coloring-matter containing sulfur and capableof dyeing unmordanted cotton from an alkaline sulfid bath in fast blackshades, which withstand the action of acids, alkalies, boiling soap,light, and air to a remarkable degree.

The coloring matter is produced by conjoint oxidation of paraphenylenediamin with an amin of the benzene series containing a free paraposition to the amido groupsuch, for instance, as anilin, orthotoluidin,or paraxylidin-in presence of thiosulfuric acid, under the influence ofwhich sulfur is introduced into the new compound. The product is a blackpowder insoluble in water and in carbonated alkalies, but dissolving inalkaline sulfids or sulfites to a dark solution. In concentratedsulfuric acid it dissolves sparingly, forming a blue-black solution. Byreducing agents, such as zinc powder and caustic soda, it is convertedinto aleuco compound which on exposure to air rapidly reoxidizes.

Example: A solution of twenty seven pounds of paraphenylene diamin intwentytwo gallons of water and three gallons of hydrychloric acid(twenty-seven per cent. H01) are mixed with a solution of thirty-twopounds of anilin hydrochlorid in twenty gallons of water. Into thismixture one hundred and twenty-five pounds of crystallized sodiumthiosulfate, (hyposulfite of soda,)

are stirred, and when dissolved there is run in a solution of onehundred pounds of sodium bichromate in fifteen gallons of wateracidified with forty-five pounds of concentrated sulfuric acid. Duringthe react-ion the temperature of the liquid is kept at from 0 to 5centigrade by the addition of ice. After standing for some time onehundred pounds of concentrated sulfuric acid diluted with fifteengallons of water are added, and the solution is boiled for an hour. Theprecipitated coloring-matter is filtered olf,washed with water, anddried The product is a black insoluble powder, which is rendered solubleby treatment with alkaline sulfids or sulfite's. From a bath containingsodium sulfid it dyes cotton a deep fast black, the fastness of which isstill further increased by subsequent passage through a bath containinga bichromate or a salt of copper.

The shade of the coloring-matter can be modified by varying theproportion of thiosulfate employed. By diminishing the thiosulfate theshade becomes brownish-black, and by increasing it it becomesgreenishblack, the bichromate being simultaneously varied.

The process which we have described above for obtaining the product ofour present invention forms the subject of an application for a patentfiled by us July 21, 1899, Serial No. 724,709.

Having now particularly described and ascertained the nature of our saidinvention and in what manner the same is to be performed, we declarethat we claim is As a new product and new article of manufacture thehereinbefore-described coloringmatter derived from paraphenylene diaminwhich forms a black powder insoluble in water dilute acids, or alkalinecarbonates, but In testimony whereof we aflix our sigma readily solublein alkaline sulfids, slightly tures in presence of two witnesses.

soluble in concentrated sulfuric acid with blue-black color, and whichby reducing agents is converted into a readily-oxidizable leucocompound; and which dyes uninor- 'Witnesses:

danted cotton direct a deep black from abatli ERNALD SIMPSON MOSELEY,

containing sodium sulfid. ARTHUR VERNON BATHo.

